This exercise focuses on your whole back,deltoids,and lats. This is one of the main foundations to back workouts. It helps give you that V-shape and get rid of that unpleasant underarm fat. Try for 10-12 reps. if pull-ups are too hard you can put a chair or stool under you to use to carry some of your body weight. There is also machines that you may use also where you can choose weight and do back/lat pull downs.